UNCONSCIOUS VITAL PROCESSES IN LIFE OF COMMUNITIES. 663 
actual income of the tribe available for their sustenance remains 200 
and no more. If the tribe instead of consuming the whole of the 
produce of its labour in its own support engages in external trade 
and exchanges some of the produce for other articles of more value to 
the tribe, there may be an increase in the income of the tribe to the extent 
by which the value of the articles received exceeds the value of the 
articles given in exchange. But the whole income of the tribe comes, 
as before, exclusively from the produce of its own labour, although 
it no longer all goes into consumption in its original form. If, now, 
some primitive arts or manufactures are practised, by which an addi- 
tional exchange value is given to the primary products, so that an 
additional quantity of consumable articles may be acquired in exchange 
for them, this added value will produce an increase to the tribal income 
to a corresponding extent. But, whatever the extent of the added 
value, or the nature of the additional work, the total value is still the 
product of the labour of the community. These conclusions are 
equally true with respect to the most barbarous tribe and the most 
highly civilised nation, but I am disposed to think that the extent of 
their practical acceptance as a rule of life varies in inverse proportion 
to the degree of civilisation. The only way to increase the income of 
a community (apart from the revenue coming from foreign invest- 
ments and apart from borrowing or stealing) is to increase the quantity 
of the produce of its labour, which can be done only by increasing 
either the number of producers or the efficiency of their labour. 
For the purpose of estimating the income of a community — that 
is, its supply of things available for consumption in the form of 
food, clothing, and shelter, and for increase — the value of the produce 
of the labour of the community must, in the case of articles which 
pass into actual consumption within the community, be taken at the 
moment when they are consumed. In the case of products exported in 
payment for other articles the value must be taken at the moment of 
export. An additional value may, it is true, be given to the articles 
imported by the application to them of labour before they in their 
turn pass into consumption, and this will be an addition to the income 
of the community, attributable, however, to the period following the 
importation. 
The fact that in existing civilised societies the exchange of goods 
is not conducted by barter, but by sale for money, or on credit, makes 
no difference. Gold and silver come into existence in a portable 
form as the result of the application of human labour to the gifts of 
Nature, in the same way as any other article of use or value. Coin 
may sometimes be treated as such an article. But, considered as 
money, coiu is a mere medium of exchange, and adds nothing to the 
quantity of the things exchanged by means of it, any more than a water- 
pipe adds to the quantity of water that passes through it. The real 
subject matter of exchange is the produce of labour. AV e are thus 
led to the consideration of that process in the body politic which is 
analogous to digestion in the animal, and by which the products of 
labour are brought into the form in which they can pass into 
consumption and perform their function of repairing waste and 
providing for growth and accumulation. It is evident that this process, 
which is for the most part unconscious, must be such that, as a 
result of it, the products are made exchangeable for the food, 
